Testing the function of calcium in programmed cell death
Supervisor: Dr Tim Weil
Project Summary
To coordinate decisions, cells read and respond to both internal and external cues. Especially during development, cell decisions must be highly regulated in both space and time. This spatiotemporal regulation is necessary to ensure correct developmental outcomes occur. These include cell contraction leading to tissue morphogenesis and programmed cell death to clear cells once their role in a process has been fulfilled.
The main goal of this project is to elucidate the molecular mechanisms underlying coordinated cell decisions in development. We use the rapid transfer of cytoplasm and programmed cell death of Drosophila nurse cells as our model system. Previous work shows these processes require an intact actomyosin network and calcium signalling. Of particular interest is how primary signals are amplified by second messengers to regulate the precise response of the cell. Prostaglandins and calcium are prime candidates for primary and secondary messengers and are responsible for the coordination of a variety of cellular responses such as cytoskeletal rearrangement and cell death.
Our experiments testing these and other factors suggest that prostaglandin synthesis inhibition results in aberrant calcium signalling and that the onset of these processes are asynchronous. Building on these exciting findings, this project aims to further interrogate the mechanisms involved through in vivo live cell imaging, genetic manipulation and mathematical modelling. Key initial experiments will be the targeted mutagenesis of identified candidates with CRISPR/Cas9, the visualisation of calcium and actin in these mutant backgrounds and mosaic analysis of mutant nurse cells.
This work is of broad interest due to the prevalence of calcium and prostaglandins as factors in coordinating cellular change which are implicated in many basic cellular processes and human diseases.
References
Drosophila Pxt: a cyclooxygenase-like facilitator of follicle maturation. Tootle TL & Spradling AC Development. (2008) Mar;135(5):839-47.
Drosophila quail, a villin-related protein, bundles actin filaments in apoptotic nurse cells. Matova N, Mahajan-Miklos S, Mooseker MS, Cooley L. Development. (1999) Dec;126(24):5645-57.
Preparing individual Drosophila egg chambers for live imaging. Weil TT, Parton RM, Davis I. J Vis Exp. (2012) Feb 27;(60).